The proposed research is concerned with the use of psychophysiological measures in the assessment of a personality dimension of neuroticism or trait anxiety. A review of the literature reveals that physiological differences have been obtained between anxiety neurotics and normal controls. Attempts to demonstrate physiological differences within a normal population between high and low scorers on self-respect measures of trait anxiety have generally failed. It is suggested that these failures may be due to any number of variables, such as inadequacies of the self-report scales, failure to control the stressfulness of the experiment, choice of physiological measure, and the methodology used in recording it. The studies of Lader and his colleagues usingg electrodermal measures of the orienting response provide the basis of the proposed experiments, as their results support the validity of these measures as indices of anxiety. The self-report scales of most direct relevance to this attempt are neuroticism (or trait anxiety) and introversion. These are to be measured by recently developed scales which eliminate response sets. Previous research using these personality dimensions and the electrodermal orienting response has yielded inconsistent results. Some of these inconsistencies can be attributed to differences in stimulus intensity, since a recent, unpublished study found interactions between stimulus intensity and both personality dimensions. From this study it appears that introversion is related to response amplitude, whereas neuroticism is related to habituation. Experiments are described which will replicate these results, extend them to male subjects, and investigate the effects of choice of electrolyte on the relationships obtained. An additional study looks at the effects of stimulus intensity when both intensities are presented to the same subject.